Pigment containing titanium-oxygen compound



, To all whom it may coacem: I

.Be it known that 1,.1V1oron MoRrrz\GoLo-' TED O FICE. VICTOR MORITZ GOLDSCHllgI/Jg'f,

rremnnr courammc TITANIUM-OXYGEN COMPOUND.

Specification of Letters Patent. Pate t d J e 2 1 v v p o No Drawing. Applcation filedMay 10, 1917, Serial- No. 167,837. Renewed October 25,1919. Serial I i I h l l p t.

SCHMIDT, a subject of the King of Norway,

residing at: Uhristiania, Norway, have 111- vented certain new and useful improvements in ligments Uontaining.11tamum-Uxygen Uompounds'; and 1 do hereby declare the following to be a full, clear, and exact description of the invention, such as Wlll enable others skilled 'in the-art to which 1t appertains to make and use the same.

'lhis invention relates to pigments which contain considerable quantlties of titamum oxygen compounds, and has for its object an improved pigment of this class and a process of producing such pigment.

As isfknown the hidingv power of a white pigment is attributable to its power of refleeting light. In the usual p gments the refraction takes place at the separating surface between each. single pigment particle and the vehicle (for instance-linseed oil).

In my other application Snllo. 126,327, filed October 12, 1917 .as a continuation of my prior application Sr. No. 156,983, filed March 23, 1917, is described a pigment in which additional refraction surfaces are mtroduced by means of providing the single pigment particles with a complex structure, so that each particle will consist of more than one component, the several components having different powers of refraction,-

whereby the hiding power of the pigment is increased. 7

In the manufacture of such complex particles it is of advantage to select for the construction of each particle substances with refractive lndexes, which are as different as possible. 1 According to the present invention s1l1- con dioxid (with a refractiveindex down to 1. 16 in sodium light) is used as a constituent of the pigment together with titanium di-' oxid' (with a refractive index up to 2.71 in sodium light). Complex pigment particles containing these substances could be produced in various manners.

, A preferred method of producing such pigments consists in combining amorphous silicon dioxid, which has the lowest refractive index of the various modifications.

of silicon dioxid, with crystalline titanium No. 333,429. j 4 v of titanium dioxid.

, ssrenoia To 'rrrniv co.

dioxidinamodification correspondin to th v, a J -m1neral rut1le,,wh1ch has the ,higli es't refractive index of the various modifications 55v l 7 produced in t'hefollowing manner.

Amorphous sllicon. dioxid or a hydrate of this compound is brought into contact with I a solution containing a soluble titanium salt for instance an aqueous sulfuric-acid solution of titanium sulfate, oneipart by weight of TiO to ten parts by weight of S10, being for instance employed.

Thesolution is evaporated whereby a residuum is obtained consisting principally of amorphous silica or hydrated silica respectively. mixed with titanium hydroxid and sulfuric acid compounds of titanium.

The residuum is calcined, whereby its content of titanium compound is converted into anhydrous titanium dioxid, the tit anium'di ox d being at suitable temperatures (for instance about 1000 centigrade) obtained in a crystalline form.

A'microscopical examination of theresulting product shows that the crystalline titanium dioxid 1s separated in theaform of,

small rutile crystals in and around the amorphous silicon dioxid particles.

These complex'particles provide a white I pigment of a very high hiding power and of a high power of resistance against chemi-v cal influences whether they are incorporated in a vehicle for instance linseed oil) alone or mixed with other pigments or fillers.

In my aforesaid application Sr. No. 196,327

'--I have disclosed a pigment comprising titanium dioxid in a more or less crystalline formation .alone or associated with amorphous titanium dioxid orwith a sulfate of an alkaline earth metal or both, anda proc-- ess of obtaining such a pigment involving the heating of an amorphous titanium dioxid compound to a sufiicient temperature to produce the desired crystallization, and I have therein broadly claimed such a process and a pigment without limitation to the presence therein or the character of other.

substances which may be associated with the crystalline titanium dioxid, and I do not therefore herein make claims reading on cles containing amorphous silicon dioxid and titanium dioxid.

2. A pigment comprising complex particles substantially consisting of amorphous silicon dioxid' and crystalline titanium dioxid. 7'

3. The process of producing pigments which comprises the evaporation of a solution' containing titanium compounds and amorphous silica.

4, The process of producing pigments, which comprises the evaporation of a solution containing titanium compounds and amorphous silica to dryness and heating the residuum to expel water and sufuric acid.

5. The process of producing pigments, which comprises the evaporation of a solution containing titanium compounds and amorphous silica to dryness and heating the residuum to expel Water and sulfuric acid, the said heating being continued so far and at so high temperatures that titanium dioxid is converted into crystalline form.

6. The process of producing a complex pigment containing artificially crystallized titanium oxid and silica, which comprises heating a compound of titanium containing oxygen together with a compound of silicon to a sufiiciently high temperature to effect crystallization in thetitanium oxid.

'7. The process of producing a complex pigment containing artificially crytallized titanium oxid and a solid oxid of another element having a refractive index different therefrom, which comprises heating a compound of titanium containing oxygen to gether with an oxygen compoundof such other element to a sufficiently high temperature to effect crystallization of the titanium oxid. r

8. The process of producing a complex pigment comprising titanium oxid, characterized by being partly amorphous and partly crystalline in structure and having intermingled with the titanium oxid a solid oxid of another element Which consists of heating a compound of titanium containing oxygen together with a compound of such element to a sufliciently high temperature to effect partial crystallization in the titanium oxid.

In testimony that I claim the foregoingas my invention, I have signed my name in presence of two subscribing Witnesses. 7

VICTOR MORITZ GOLDSOHMIDT. \Vitnesses:

G. VARMAN, G. FABRIo Us HANSEN. 

